Dietrich agreed to a contract with the Nationals on Friday, Jesse Dougherty of The Washington Post reports.
The 31-year-old opted out of his minor-league deal with the Yankees last weekend and didn't take long to join a new organization. Dietrich's deal with the Nationals is also believed to be a minor-league pact. He hit .215/.413/.393 with five homers and a 32.2 percent strikeout rate in 143 place appearances at Triple-A before parting ways with New York.